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URL of this page: https://medlineplus.gov/laboratorytests.html

Laboratory Tests

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Summary

Laboratory tests check a sample of your blood, urine, or body tissues. A technician or your doctor analyzes the test samples to see if your results fall within the normal range. The tests use a range because what is normal differs from person to person. Many factors affect test results. These include:

  • Your sex, age and race
  • What you eat and drink
  • Medicines you take
  • How well you followed pre-test instructions

Your doctor may also compare your results to results from previous tests. Laboratory tests are often part of a routine checkup to look for changes in your health. They also help doctors diagnose medical conditions, plan or evaluate treatments, and monitor diseases.

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The information on this site should not be used as a substitute for professional medical care or advice. Contact a health care provider if you have questions about your health.